linux-kernel - [PATCH 2/7] UBI: fastmap: avoid multiple be32_to

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Message-Id: <1471937574-8045-3-git-send-email-boris.brezillon@free-electrons.com>
Date:   Tue, 23 Aug 2016 09:32:49 +0200
From:   Boris Brezillon <boris.brezillon@...e-electrons.com>
To:     Artem Bityutskiy <dedekind1@...il.com>,
        Richard Weinberger <richard@....at>
Cc:     David Woodhouse <dwmw2@...radead.org>,
        Brian Norris <computersforpeace@...il.com>,
        linux-mtd@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Boris Brezillon <boris.brezillon@...e-electrons.com>
Subject: [PATCH 2/7] UBI: fastmap: avoid multiple be32_to_cpu() when unneccesary

process_pool_aeb() does several times the be32_to_cpu(new_vh->vol_id)
operation. Create a temporary variable and do it once.

Signed-off-by: Boris Brezillon <boris.brezillon@...e-electrons.com>
---
 drivers/mtd/ubi/fastmap.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/mtd/ubi/fastmap.c b/drivers/mtd/ubi/fastmap.c
index a26dcc9d7703..ebb65ac6980f 100644
--- a/drivers/mtd/ubi/fastmap.c
+++ b/drivers/mtd/ubi/fastmap.c
@@ -370,24 +370,24 @@ static int process_pool_aeb(struct ubi_device *ubi, struct ubi_attach_info *ai,
 			    struct ubi_vid_hdr *new_vh,
 			    struct ubi_ainf_peb *new_aeb)
 {
+	int vol_id = be32_to_cpu(new_vh->vol_id);
 	struct ubi_ainf_volume *av;
 
-	if (be32_to_cpu(new_vh->vol_id) == UBI_FM_SB_VOLUME_ID ||
-		be32_to_cpu(new_vh->vol_id) == UBI_FM_DATA_VOLUME_ID) {
+	if (vol_id == UBI_FM_SB_VOLUME_ID || vol_id == UBI_FM_DATA_VOLUME_ID) {
 		kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 
 		return 0;
 	}
 
 	/* Find the volume this SEB belongs to */
-	av = ubi_find_av(ai, be32_to_cpu(new_vh->vol_id));
+	av = ubi_find_av(ai, vol_id);
 	if (!av) {
 		ubi_err(ubi, "orphaned volume in fastmap pool!");
 		kmem_cache_free(ai->aeb_slab_cache, new_aeb);
 		return UBI_BAD_FASTMAP;
 	}
 
-	ubi_assert(be32_to_cpu(new_vh->vol_id) == av->vol_id);
+	ubi_assert(vol_id == av->vol_id);
 
 	return update_vol(ubi, ai, av, new_vh, new_aeb);
 }
-- 
2.7.4